Christian Heilmann

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Archive for April, 2019

A checklist for more inclusive, accessible, measurable and understandable talks

Tuesday, April 23rd, 2019

Chris Heilmann presenting

I’ve spent the better part of the last seven years presenting at all kind of conferences, meetups and client meetings and I’ve learned a lot along the way. I learned about different needs of different audiences and how to prepare your talk to make it as easy as possible for organisers to work with you. More importantly, though, I learned how to ensure that my presentations can be understood, don’t offend and work in even the worst organised environments.

In order to share this knowledge, and to remind myself of the necessities I put together a checklist to fill out before my talks. Not all of these bits are applicable to the talk you may give, but it is a good reminder of what you can do to help others understand what you do. And to make sure you can show your company what you did.

I hope this helps!

Getting started with Javascript – The right tools and resources (Video Interview)

Thursday, April 18th, 2019

A few weeks ago I was in Paris, France to visit Prismic and they interviewed me about the JavaScript vs. CSS debate. In 10 minutes we covered a lot :).


Here is a verbatim transcript of what we talked about:

Hi, Chris. We are here at Prismic, very happy to have you there. Could you maybe first introduce yourself?

Hello, I’m Chris. I’m a principal software developer at Microsoft, and I’m dealing with all matters web there, ‘cause I’ve been doing it for 20 years, and I love the web.

Okay, you also love JavaScript, I know that, and I’m sure you interact a lot with JavaScript developers, so I’m curious to know, like, where would you recommend someone who wants to learn about JavaScripts, to go and learn more about it?

The problem is, nowadays, there’s far too much JavaScript it’s overwhelming and everybody has a different opinion of it, so you actually have a lot of resources that are outdated, some of them that seem to be simple, so there’s a few things that source of truth that I love to use. One of them is the Mozilla Web Docs, MDN Developer Network, used to work on that one when I worked at Mozilla. That one is an up-to-date information that is actually everything about web technologies, is it CSS, JavaScript? And every time you wanna lookup some JavaScript that is a great way to look up. You can even do that in browsers when you do MDN and space and then the JavaScript that you wanna look, it automatically gets the results from MDN back so you don’t have to go through the website and do it there. Another very interesting thing is is a website that allows you to say something, technology that you heard about, and say which browsers and which environments support them.

So if it’s safe for you, in your case for your product, to actually use these already and also links through the documentation of these things links through the problems that they may have and links through the W3C standard that is actually their source of truth for everything but it’s not as easy to understand. So these are the main resources that I think are a great way for people to get started. And of course look around for videos on YouTube and conference videos because all of them are available for free. Every conference spends a lot of money producing these things and giving them out, so it’s kinda weird ‘cause people watching this right now so this kinda matter. But look at these resources and make sure you look at the date as well ‘cause some of them get outdated rather quickly, but something like MDN the great thing is it’s not a Mozilla product, it’s basically an independent product that people from Microsoft, Google, Apple, Samsung, whoever is doing something on the web are contributing to that one. We realize this is the one resource. We want to keep up-to-date, so this is a great place to start.

Okay, cool. So once they have looked this knowledge, where should they start, which tool should they use?

Once you have all this knowledge you would in the 70s and you don’t have to work anymore because it’s a lot of knowledge to take in. But knowing where to go is always a good opportunity. I find the most important thing right now and the most biggest change for me as well, is that how tooling has become so much better than it used to be in the past. In the past we had an alert to basically say when something went wrong in our JavaScript and that was not fun. Nowadays every browser comes with developer tools. There’s Chrome developer tools, there’s F12 developer tools, Safari’s, Firefox’s, they all differ a bit to a degree but they all give you lot of insight of what you’re doing and what you’re doing wrong. So instead of getting the old error messages, undefined is not defined which is not as helpful. You nowadays have a console in every browser that tells you what went wrong. And sometimes it’s even crosslinked to the MDN documentation that you can click on and know why something went wrong. So knowing these developer tools in the browsers, in and out or at least basically, is a very very good start for you because you know what you’re doing and you don’t need to go anywhere else. You can actually start writing JavaScript directly in those. Another great thing to get into is using interactive playgrounds on the web like: JS Bin for example, JSFiddle, CodePen, just a few others, StackBlitz and these kind of things. CodePen is a beautiful beautiful example because it has documentation, it has articles and it has code examples. So what these things allow you to do is write a code example when you run into a problem and send it to other people and they can then see what you’ve been doing and help you fix the problem in context rather than you having to explain to them what you did wrong. You can do live coding together with each other in these kind of environments. So for trainings and for schooling courses that I do, these things are beautiful to see. So getting to know these kind of environments and CodePen is full of very creative code examples so that’s a beautiful thing. If you’re just a visual learner, this is something to get very excited about. When it comes to setting up your environment I think Visual Studio Code is the editor that, of course I’m kinda biased because I work with the thing and on the thing, but it’s also a product that allows me to write code and learn what I’m doing wrong while I’m doing it. So there’s linters built into the systems, so linting means, while I’m typing something it tells me By the way this is wrong and here’s why. So much like the squiggly lines in Word when I’m writing something telling me I mistyped this, it’s the same happening in JavaScript. And the other thing it does for you is a lot of code insight so you don’t need know every keystroke but you actually tells you, you wrote these three letters, you probably want to write that long word now. and auto-completes it for you and the only one that can come after that is that one and so on and so forth. So it made me a much more effective developer and it’s lightweight, it’s open source, you can install it on Linux, on Mac, on Windows and you don’t have the problem that you had before like the editor had some similar functionality were like 12 gigabyte downloads and that’s not fun to do as well. So that’s one of the things I would be considering because it’s a beautiful experience of learning to become a better developer while you’re programming. Not reading up on it and having to know everything before you’re doing it. The tooling we have nowadays with developer tools and the browsers and editors like Atom or Visual Studio Code is that they do this auto completion things for you so it teaches you new things while you’re typing and you’re actually experiencing code as an adventure.

Okay, and one last question is, what would you start with like as your first project?

Whatever tickles your fancy, whatever makes you happy. I think products that come out of passion, things things that are something that you always wanted to build for yourself are the best things that are out there. You don’t want to start writing Facebook, that’s probably not a thing you’re gonna do in the weekend. But something you’re already excited about and you always wanted to play with is a great thing to get started with. One of the main things that I think are education space is not built on that kind of environment yet, it’s like, here’s a very very weird thing to do, Let’s find an algorithm to do that kind of thing. Solve your own problems and if that’s a to-do list for your things, if it’s organizing your kitchen, if it’s something you always wanted to do, if it’s finding out why the planes are not right at this moment. Friends of mine live on an island where there’s lots of ships coming in and they actually wrote themselves an app to learn code, to know when a cruise ship is coming in because then it doesn’t make no sense for them to go to town because it’s gonna be full of tourists. I guess Paris has similar things so that might be an app to start with kind of thing. Programming is there for us to do tasks that we are bored of as users. Computers are there for us to do the things that we humans would be bored doing. So find something like that that makes you happy and that way go out there. If you wanna learn new programming as well, you wanna learn JavaScript, there’s lots of good courses out there to get started with. But don’t get overwhelmed by the seemingly complexity of it. You can have tools nowadays that get you every step on the way and it’s in an interactive fashion and not, oh, you’re stuck here because you don’t know. The information is free and the tools are free and that’s why this is a wonderful world right now to learn web development.

Okay, cool. Well thank you very much for being there.

Javascript vs. CSS – More control means more responsibility (video interview)

Thursday, April 11th, 2019

A few weeks ago I was in Paris, France to visit Prismic and they interviewed me about the JavaScript vs. CSS debate. In 10 minutes we covered a lot :).


Here is a verbatim transcript of what we talked about:

So I’m here at Prismic, with Chris Heilmann. Chris, can you introduce a little bit yourself what you’ve been doing?

I’ve been web developing for 20 years, now I’m a Principal Software Developer for Microsoft working on all web tooling there and the browser.

Right. You are working on EDGE, right? – Yes.

So there’s a question that comes quite often is like JavaScript vs. CSS, you know when to use one, can we do everything with JavaScript? Should we do everything with CSS?

It’s a massive topic at the moment and it’s actually splitting our market into two camps or three camps or four camps. And I find it kind of depressing because the technologies have always been there. JavaScript was always, a technology that allows you to do everything on the web, but you also own everything. You own the performance of it and you’re on the rendering of it and you own the accessibility of it. Whereas a standard, like HTML already gives you a lot of accessibility benefits from the beginning. A button works like a button and the button is also available to somebody who can’t see it because they get it read out as a button. In JavaScript, I can make that button work perfectly the way I want to, but I’d also have to control everything that is necessary to be done that a blind user can use that thing, that it works on a mobile device and that it works on these kinds of things. CSS is the same thing. It’s too easy to do everything with JavaScript. That’s why people get very excited about it.

This is the feel of control, right? You can control every little detail.

And to do it fast as well. You can do it in one goal, you can do it, you could control everything yourself. You don’t need to talk to other people who are experts in that. But this is not how interfaces for the web are being built, because it needs experts that know about the problems of different end users, of different environments, of different ways where your application will run. Blindly trusting a technology or a framework to actually do that for you, it’s not a good bet to me. So one of the main things that a lot of JavaScript people that basically the new kind of jobs people say everything JavaScript is necessary, keep saying that CSS isn’t good enough. That CSS is a weird standard and it’s not the way we learn programming. And that’s totally true. It’s not meant to be JavaScript, it’s meant to be a different technology. But it has come into its own over the last years immensely, CSS is not as confusing and weird than it used to be in the past where browsers didn’t quite support them. All browsers that we have now, are evergreen, all of them support the CSS that we expect them to support. So it’s not only about changing colors, it’s also about animations that actually get accelerated by the machine for you, by the browser for you. There’s transitions and there’s a finally a proper layout environment in CSS. With grid layouts we can create page layouts that are highly complex, and the browser does the rendering for us, we don’t have to do the calculations in JavaScript ourselves and to write in-line styles and these kinds of things. Flexbox gives us the opportunity to have little components, that are actually flexible and are taking up as much space as we want to. So the holy grail of like centering something in vertical and horizontal is now two lines of CSS. It’s not about knowing how browsers do it wrong. It’s not about putting in extra elements.

So it what the case, right? It’s by block align, all the kind of thing, yeah. You had to kind of always know exactly how the browsers are behaving and now it’s a standard, there’s Flexbox, you express what you want and it’s implemented.

Exactly. I think the big problem with CSS is that people see the big failures of old browsers as a part of the heritage of CSS. And it’s not the case any longer. CSS evolved as much as JavaScript did over the last few years as well. So JavaScript now is a standardized language finally, with ES5, we finally had an ECMAScript standard and not just like something that, that browser does this, that browser does that, we hope that browser does this, so we now have a standardized way there. So, I think both are as powerful as they can be. JavaScript, is the only one that allows you to do everything in one go. That’s why it’s very tempting to do it. But what we do with it is we lock out a lot of people, that could be efficient people working in our market by asking them to do a technique to learn one technology, where they actually are excited about doing other things.

That’s a cultural problem, right? Like you, what you mentioned is that you feel like if you don’t know JavaScript, then you are not fit enough for doing web development.

And that’s a very arrogant and stupid statement to make because if you don’t know CSS, are you then as incompetent? And most JavaScript people that just know JavaScript and don’t wanna touch CSS cause it’s kind of different. You know what? Different people work in teams together to build interfaces. So let people specialize on the different parts that make the most sense in your interface, where the browser can help us rather than we have to fight against the browser.

So the browser will help us with what? in CSS?

In CSS it helps us with the rendering of different interfaces, if you use grid, if you use Flexbox, it also helps us with the animations. So it’s helps us with the coloring. It helps with the fonts, all the things that you actually want to have. And it helps us with caching as well. A CSS file can get cached and can get reused by the browser. Whereas if you render something, every single time on every single frame differently, because you want to have full control of your animation, it cannot get cached and it will have to download the whole bunch every single time just because you want that control.

Right. So like for instance, here’s an example, why is it problematic to have a SPAN? And you know, kind of put a link, an action on it, an event on it and make it look as a button? What could go wrong?

A SPAN does nothing. A DIV has no semantic meaning. A DIV could be anything. It’s a placeholder. If think about it, it’s a variable, it has been undefined in CSS, so to say. Not really, but it’s nothing. Whereas a button already when you tell a button in HTML, the browser renders it as something clickable, it tells somebody who is blind that this is something clickable as well. It gives you a depressed state. It gives you a state that is invalid. It gives you a state where it’s greyed out that you can just control with an attribute as well, Like all the different UX states of a button that you have to define if you use a , are already given to you in the browser because it’s built-in. Of course, it might not be to your liking the way it looks, but in the past we couldn’t style it. Nowadays, styling of buttons is completely possible, across all the browsers that we have nowadays as well.

Another example is that in input fields for select for instance, it’s like the first time, I noticed it, a long timeago, whenever you click on a select box instead of trying, in your mobile phone, to kind of find the actual state that you want to select, it opens something down, which is much bigger, which is like much more visible.

All form elements have an operating system defined look and feel like; an input type date gives you a calendar, that you don’t have to program yourself, How cool is that? It’s even localized to the environment. So it will be an American date picker, with the date the other way around that we have. And these kinds of things. That is already built for you into the browser if you use these things. Even more importantly if you use a proper input element with an input type=”email”, input type=”URL” and so on and so forth. Input type=”password”, the browser can do the storing, can store the data for you and fill it out. So every single time I use my mobile phone to order something, I don’t want to enter my address. If the address field has been properly marked up in HTML, the browser says like, “Hey, shall I auto fill these things for you?” And I’m more likely to buy things from you if I can use that auto-fill, then if you give me that perfectly rendered JavaScript controlled input element that is not an input. –

*Right. Completely. Okay then, when does it make sense actually to use frameworks and JavaScript
frameworks and components instead of using like CSS and HTML What is the right decision? Is it the size of the team, the size of a project?*

It’s more an architectural decision than anything else. If your environment, if what you build is consisting of lots of little changing parts, that are not interacting with each other and are not and cannot interact with each other, then the component framework makes so much more sense because that’s what it was built for. The web was not built as a platform to do these kinds of things as of yet. We’re working on standards to think about it in that direction as well.

Just like – Web component of course—- Web component

But not everything needs to be Facebook, not everything needs to be Twitter, not everything needs to be LinkedIn. If your website is more or less static pages, then using a component framework makes no sense, but if you’re a website is something where you have 12 different departments controlling 12 different parts of the interface, and they all wanna have to a different look and feel and they want to have their own data consumption and data going back and forth to directional without interfering with the others, then a component framework, it’s the right way to use it. So it’s the right thing for the right job. So in this case, the complexity, that a framework allows you to do is something that not every time is applicable to a normal web environment. But if you do it, it makes no sense to actually, demonize frameworks and say like, you should never use frameworks as well. In the case of React of course the other part, the other part is that it also allows you to render out binaries for iOS and for Android, If you don’t wanna play on the web and you wanna play into those markets. And that’s a great thing because you built it once and you deployed it in three different environments. You can do the same thing with HTML and PWAs nowadays, but it’s much, much easier to have one controlled environment. You have to think about the cost. You have to think about what I want to do, what can I do that the browser does a lot of stuff for me or the web does a lot of things for me already, that are accessibility, that are about accessibility, that are about the rendering in the browser, or do I wanna have full control over it because I need to violate some of those ideas, I need to make them differently. Then your reliance on something like a framework makes total sense. You also have to think about like what’s happening in three, four, five years time. And that every of your end user needs to download that whole framework before the first thing renders on their device. So it’s a matter of architecture. I really, really don’t think that there’s a space where only HTML CSS is applicable. JavaScript gives us a lot of benefits. But it should not be the case that you’re not a full developer if you don’t know JavaScript, cause on the web, that doesn’t make any sense.

It makes sense. Thanks Chris

Common accessibility issue: moving to a page section without shifting keyboard focus

Tuesday, April 9th, 2019

Disclaimer: the following is not a dig at JSFest, I just used their website as a demo at the event. It is a common problem many people have on their sites, so it is a good example to use.

One feature you see on a lot of “modern” web sites is that activating the menu items smoothly scrolls to the section you chose. It is good UX, as people see that they are going to another section. It also feels much smoother than simply jumping to it. When there are any JS errors, you still have a full page you can scroll. If you properly linked your navigation items with links pointing to fragment identifiers, it even works without JavaScript and as a bookmarking feature.

  <li><a href="#cakes">Cakes</a></li>
  <li><a href="#cookies">Cookies</a></li>
  <li><a href="#desserts">Desserts</a></li>
  <li><a href="#remedies">Remedies</a></li>
</ul><h2 id="cakes">Cakes</h2><h2 id="cookies">Cookies</h2><h2 id="desserts">Desserts</h2><h2 id="remedies">Remedies</h2>

However, we can really make it hard for keyboard and screenreader users when we forget to set the focus to the element we scrolled to. Just because it is in the viewport, doesn’t mean the keyboard focus moved there.

What does this mean? Let’s take a look at this screencast. As a keyboard user, you need to hit “tab” seven times to reach the “prices” link. Activating it does scroll the correct section into view. However, if all you can do is hit tab and you can’t see the change, it needs an additional 107(!) “tab”s to times to really reach the section.

The remedy is easy:

  • Ensure that your target sections of your menu are keyboard accessible landmarks in the document with IDs. This also has the benefit that anyone following a “” link will get to that section
  • After you scrolled to the section, move the keyboard focus programmatically from the menu item to the target section using focus() and – if needed – by setting a tabIndex.

If you want to test this on your own sites, install the accessibility insights extension for Chrome or (new) Edge.
You will get a heart icon in your browser and a choice of tools to run on the current site:

accessibility insights extension options after install

Select the “Ad hoc tools” to get the extension to overlay accessibility issues on the current document:

Ad Hoc Tool options of accessibility insights

Once you turned on the “Tab Stops” option you get a confirmation that the extension is running:

tab stops enabled

Hitting tab now will start showing you the tab stop journey across your document, which helps you find issues like these. Often these are easy to fix, and make a huge difference.

Hinting at a better web at JSFWDays in Kiev, Ukraine

Monday, April 1st, 2019

Two weeks ago I went to Kiev, Ukraine to speak at the JavaScript FWDays conference. I gave the closing keynote talking about what matters on the web and how we can create a better one by moving our best practices into our development flow.

presenting in the huge room

The video is now available on Youtube

The slides and resources mentioned in the talk are available on

View Hinting at a better web FWDays edition on Notist.